Getting the right sound from a clock requires a combination of engineering skill and musical knowledge. If you have a gong rod that sounds flat, or is even missing altogether, you will need to calcualte the note it should make when struck.

Material dealers sell complete tuned sets of rods for Westminster chime clocks, and this is often the simplest answer for the amateur. If the cast base is missing, then these are available with tuned rods already fitted.

There is no standard location or sequence for the rods, so you may need to re-arrange them in the block. Blocks need to be clamped or screwed very securel to the case to get a good sound. 

The Westminster chime uses four notes, and although they can be found with five or even eight rods, this is simply to make the same tune sound better. The four play the tune and the fifth can be used to strike the hour. On 8 rod Westminster chime sets, the remaining four are often struck as two pairs on the hour.

Some clocks use six or eight rods to play more complex tunes, and these need to be made from loose un-tuned gong rods.

Sequence of notes for WESTMINSTER CHIMES
1/4: g,f,e,b.
1/2: e,g,f,b, e,f,g,e.
3/4: g,e,f,b, b,f,g,e, g,f,e,b.
4/4: e,g,f,b, e,f,g,e, g,e,f,b, b,f,g,e.